Hot-air engine.



' PATENTED SEPT 15, 1903. W; R. KENNEDY. HOT AIR ENGINE.

APPLICATION FILED nu 9, 1901 I0 MODEL.

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. w. R. KENNEDY.

HOT AIR ENGINE.

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U IT D STATES Patented September 15,

PATENT OFFICE.

HOT-AIR ENGINE.

SPECIFICATION forming part of Letters Patent No. 739,187, dated September 15, 1903;

Application filed May 9,1961.

To all whom it mayconocrn:

Be it known that I,WILLIAM R. KENNEDY, a citizen of the United States, and a resident of Newark, Newcastle county, Delaware, have invented certain Improvements in Hot-Air Engines, of which the following is a'specification.

My invention relates to hot-air engines; and it consists of certain improvements in such engines of the Ericcson type, the object of my invention being to produce greater efficiency in engines of this class, to facilitate the movement of the pistons and the working of the pump, to regulate the speed of the engine, and to reduce the number of parts of the same.

My invention is fully illustrated in the accompanying drawings, in which Figure 1 is a sectional elevation of .a hotair engine of this type, showing my improvements applied thereto. Fig. 2 is a plan view of the same;- and Fig. 3 is a sectional view of the cylinder, taken on the line a a, Fig. 1, showing a plan view of the piston. Fig. 4 is a vertical section of the cylinder, illustrating a modified form of piston. Fig. 5 is an enlarged view of adetail of the invention. Figs. 6 and 7 are respectively side and front elevations, on an enlarged scale, of the crank and Fig. 8 is an enlarged sectional view of the connection between the beam and the pump-plunger.

' In engines of this type as ordinarily constructed the working pistonis connected directly to the beam,'the latter operating the transfer-piston through an elaborate system of mechanical devices comprising bell-crank levers, connecting-rods, and a counterweight. For these parts I propose to substitute a chain or a flexible wire rope or cord, one end of whichis connected to a crank operated by the beam, the other end being connected to a rod extending from the transfer-piston and passing through the working piston of the engine. The cylinder of my improved form of this type of engine is made in two parts (greatly facilitating the casting of the same) to provide the annular chamber forming the water-jacket. The connection between the pump-rod and the beam of the engine is made yielding, so that the jerking or thumping of the pump is prevented. A slight lost motion serial No. 59,432. (No model.)

is thus provided for, which permits easier action of the beam and does away with the rigid release of the pump-plunger in the water.

In the drawings'herewith, 1 represents the fire-chamber-of an ordinary Ericcson hot-air engine, which in the present instance may be arranged to burn either solid, liquid, or gaseous fuel. 2 is the cylinder of the same, having the depending portion 3 extending into the fire-chamber.

4 is the working piston, and 5 is the transfer-piston, extending into the depending portion 3 of the cylinder 2.

Journaled in a suitable bearing 6, mounted on the upper portion of the cylinder 3, is the beam 7, connected at 8 to the links 9 of the working piston and at 10 to the pump-rod 11.

12 is a fly-wheel carried by a shaft 13, which is journaled in suitable bearingsin the frame 1 1. Secured to the fly-wheel shaft 13 is a crank 15, to which the beam 7 isconnected by means of the link 16.

The transfer-piston 5 has a rod 17 projecting therefrom, said rod passing through a stuffing-box 18, carried by the working piston 1. To the upper end of this rod 17 a chain 19 is secured. This chain passes over aguidepulley 20, journaled in the upper portion of a bracket 21, mounted above the cylinder 2, thence around another guide-pulley 22, journaled in a bracket 23, secured to the under side of the beam-support 6, and is attached to an adjustable yielding support or connection 24., carried by thecrank 15. In place of the chain I may use a flexible wire rope or cord, which should be connected inthe same manner as the chain.

The link16, connecting the crank and the beam, is provided with a strapped end 25,

whereby it may be readily secured to,the 1 grooved boss 26, carried by said crank; This boss 26 is provided with a pivot -pin 27, arranged eccentrically to the same, and said pivot-pin 27 carries the connection 24, the lat ter being held in place by a suitable .nut. This connection, which is shown more clearly in Fig. 5, comprises the member 28, having bolts 29 threaded therein and held in place by the locking-nuts 30, the plates 31 and 32, carried by said bolts and serving tospace the same apart, and the short rod 33, secured'to the plate 31 and passing through the plate 32,

to which rod the chain 19 is secured at 34. To provide the necessary cushion and make the support or connection 24 yielding, a spring or springs is connected therewith. As shown in the drawings herewith, I prefer to use a coiled spring 35, surrounding the rod 33 and interposed between the plates 31 and 32.

The beam 7 of the engine is journaled in a suitable bracket 6, carried by the cylinder 3. Supporting said beam are bolts 36, preferably provided with tapered ends, which fit corresponding recesses in the beam, and these bolts are threaded into the bearing 6, so as to be adjust-able, locking-nuts 37 being provided for the purpose of maintaining them in position when properly adjusted.

The cylinders of hot-air engines of this type are provided with annular chambers for the reception of a cooling fluid to reduce the temperature of the hot air in the upper portion of the cylinder, such condition forming a part of the operation of the engine, and when such engines are used for pumping water such water passes into the annular chamber directly from the pump, circulates within said chamber, and is conveyed away for use from any suitable point.

The cylinders just noted have usually been made from a single casting; but when so made it has always been a difficult matter to make the annular chamber. To obviate this difficulty, I make the cylinder in two parts and secure such parts together in a novel manner, providing the chamber 38 for the circulation of water, as hereinbefore noted. The sections of the cylinder are secured together at the bottom by bolts 39, a gasket of asbestos or other suitable packing material 40 being interposed between the flanges of the sections. At the top of the cylinder the outer section is provided with an internal flange 41, having an annular groove 42, adjacent to the wall of the inner section. This construction forms the annular recess 43, into which lead or other easily-fused metal 44 may be poured to make a perfectly-tight joint at the top of the cylinder.

In Figs. 1 and 4 I have shown sectional views, in elevation, of the working piston which I employ with this form of engine, Fig. 1 being the preferred form and Fig. 4 illustrating a change in one of the details of such piston. This piston consists of the circular disk 4, having a leather washer or packingring 45, arranged in an annular recess on the under side of the disk, which washer is held in place by an annular ring 46, located in said recess and secured by a series of bolts 47. the piston to prevent the oscillation or wabbling of the same, I provide the outwardlyprojecting arms 48, secured to the top of the disk 4 and so disposed as to contact with the inner surface of the cylinder some distance above the piston. These arms 48 are secured in place by the bolts 47 which hold the leather washer in position. The arms of the In order to provide st-eadying means for piston shown in Fig. 1 have but slight contact with the inner walls of the cylinder 2; but in Fig. 4 I have shown a modified form of arm 48, extending for some distance above the piston and having its entire surface in prevent the drag on the plunger in both di:

rections, I provide a yielding connection for the beam and pump-rod, as clearly shown in Fig. landin sectional elevation, Fig. 8. Depending from the end of the beam is a forked bracket 49, pivotally connected thereto, and supported within this bracket by means of a spring 50, which is interposed between an adjustable nut 51 and the lower portion of the bracket, is a rod 52, carrying at the lower end a block 53, having a pivot-pin 54, from which the upper end of the pump-rod is hung. A leather washer 55 is preferablyinterposed between the lower portion of the bracket and the block 53. The rod 52 is square, passing through a squared opening in the lower portion of the bracket, and the upper end of the rod is threaded for the reception of the adjusting-nut 51 to regulate the tension of the spring 50. This spring affords relief to the pump-plunger on the upward movement of the latter by permitting a slight lost motion to the pump-rod, which is taken up by said,

spring.

In engines of this character as usually constructed the transfer-piston is positively depressed by means of suitable arms or links operated by a bell-crank lever which receives its movement from the usual crank operated by the beam. Under such conditions the movement of the piston is as follows: During the upward movement of the transfer-piston the cool air from the upper part of the cylinder will be transferred by said piston through the annular space between it and the cylinder to the lower part of the latter, which is heated as hereinbefore set forth. The air so transferred becoming heated expands in the lower part of the cylinder, and its expansion causes it to force the working piston upward. This movementof the transfer-piston is about three-fourths completed before the working piston commences its upward movement, by which its work is done, and when the working piston has nearly completed the upward or working stroke the transfer-piston begins to descend and force the hot air back from the lower heated portion of the cylinder to the upper cool part of the same, said piston completing its stroke by the time the working piston has made about one-third of its return stroke. In my engine, however, the rod which extends from the transfer-piston is connected to thecrank 15, operated by the beam 7 by means of a chain, wire-rope, orcord. Hence said piston cannot be positively lowered in the cylinder by the movement of the beam. To overcome this apparent difficulty, however, I arrange the pistons within the cylinder in such relation to each other that the downward movement of the transfer-piston is assisted by the downward movement of the working piston, such movement being communicated to the transfer-piston by the body of air between the pistons, which is constantly increased in volume as the transferpiston descends and displaces the air in the lower part of the cylinder. As the working piston is moved downwardly by positive connections and as there can be no compression of the air between the pistons, the movement of the working piston assists the downward movement of the transfer-piston, and the air displaced by this movement passes around the ,transferpiston to the space above the same. This action is maintained until the transfer-piston and the working piston have decended to their lowermost positions and the crank has completed its turn, tightened the chain, and is ready to again lift said transfer-piston in the cylinder.

To prevent any jerk on the crank by the descent of the piston, such action usually accompanying an increased speed of the engine, I attach the chain to the yielding support or connection 24, already described. The spring carried by this support is sufficient to take up most of the slack when the latter occurs, and when the transfer-piston reaches the limit of its downward movement the spring will not be compressed until the crank completes its turn and begins to pull on the chain to raise the transfer-piston. By this arrangement there is no jerk on the crank when the transfer-piston descends; a matter particularly desirable, as said piston is carried down by the pressure between itand the working piston, and such movement if not retarded would tend to jerk the crank when the piston reaches its limit of movement.

In order to regulate the speed of the engine and retard the movement of the transfer-piston should it become excessively fast, I provide means for permitting the hot air to escape from the cylinder. For this purpose I arrange the small pipe 56, leading from the cylinder. Closing the end of this pipe is a washer 57, carried by the short arm of a bell: crank lever 58, which lever is pivoted at 59 to the fire-chamber. The other end of this bell-crank lever is forked. Carried by one of the fork members 60 is a weight 61, adjustable thereon, by means of which the washer 57 may be held firmly against the open end of the pipe 56. The other fork member 62 projects almost vertically and carries an adjustable piece 63, which latter member is in 26, to which the link 16is strapped. This arrangement, which is clearly shown in' Figs. 6 and 7, while not afiecting the movement of the beam and the movement of the working piston in the cylinder or the working of the pump, gives an extra range of movement to the transfer-piston, so that the latter has plenty of room to work in, and said piston having a flexible connection with the crank the change of movement takes place without stiffness and without any jerk or binding of the piston and its connecting and moving parts. I

Having thus described my invention, I claim and desire to secure by Letters Patent 1. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of, a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links connecting the working piston with the,

crank, a rod extending from the transfer-piston through said working piston, and a flexible connection between the crank and the transfer-piston, said connection being at-,

tached at one end to the rod from the transfer-piston and at the opposite end'directly'to the crank.

2. The combination in ahot-air engine, having a cylinder, crank and crank-shaft, of, a working piston and a transfer-piston in said cylinder, means including pivotally-mounted. links connecting the working piston with the. crank, a rod extending from the transfer-piston through said working piston, and a yielding flexible connection between the crank and the transfer-piston, said connection being attached at one end with the rod from the transfer piston and at the opposite end directlyto the crank.

3. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said. cylinder, meansincluding pivotally-mounted 1 links connecting the working piston with the. crank, arod extending from the transfer-piss ton through said working piston, and a chain connecting the crank and the transfer-piston, said chain being attached at oneend to the rod from the transfer-piston, and having a flexible connection between its opposite end and the crank.

4. The combination in a hot-airengiue hav-.

ing a cylinder, crank and crank-shaft,'of.a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a yielding flexible connection between the crank and the transfer-piston, and means for guiding said flexible connection, said connection being attached at one end to the rod from the transfer-piston and at the opposite end directly to the crank.

5. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a yielding flexible connection between the cran k and the transfer-piston, and pulleys adapted to guide said flexible connection, said connection being attached at one end to the rod from the transfer-piston and at the opposite end directly to the crank.

6. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links a beam and a rod connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a flexible connection between the crank and the transfer-piston, said connection being attached at one end to the rod from the transfer-piston and at the opposite end directly to the crank, and means connected to said flexible connection for retarding the movement of the transfer-piston in one direction, substantially as described.

'7. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links a beam and a rod connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a flexible connection between the crank and the transfer-piston, said connection being attached at one end to the rod from the transfer-piston and at the opposite end directly to the crank, and a spring attached to said flexible connection and serving to retard the movement of the transfer-piston su bstantially as described.

8. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links a beam and a rod connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a flexible connection between the transfer piston and the crank, connecting means for said flexible connection, and means combined therewith for retarding the movement of the transfer-piston, substantially as described.

9. The combination in a hot-airengine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links, a beam and a rod connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a flexible connection between the crank and the transfer-piston, and a spring attached to said flexible connection and serving to retard the movement of the transferpiston in one direction.

10. The combination in a hot-air engine having a cylinder, crank and crank connection, of a working piston and a transfer-piston in said cylinder, means including pivotally-mounted links a beam and a rod connecting the working piston with the crank, a rod extending from the transfer-piston through said working piston, a chain connecting said rod with the crank, a yielding support carried by said crank to which the chain is attached, a spring carried by said support in operative engagement with the chain connection, and a fixed portion of said support against which the spring is compressed, the compression of said spring serving to retard the movement of the transfer-piston in the cylinder.

11. The combination in a hot-air engine, of the character described, of the crank for operating the Working piston and the transferpiston, said crank having a spindle at its free end from which a connection is made with the working piston, a pin mounted eccentrically on said spindle, and a connection between said pin and the transfer-piston whereby said piston is permitted an increased range of movement.

12. The combination in a hot-air engine of the character described, of the crank for opcrating the working piston and the transferpiston, said crank having a spindle at its free end from which a connection is made to the working p'iston, a pin mounted eccentrically on the end of said spindle, and a flexible connection between the transfer-piston and said pin, whereby said transfer-piston is permitted an increased range of movement.

13. The combination in a hot-air engine of the character described, of a cylinder, and a working piston adapted to said cylinder, said piston having a series of arms contacting with the wall of the cylinder above the piston, and having packing to make the proper fit of the piston, with means for securing said packing in place, including a series of bolts which also serve to secure the steadyingarms to the piston, substantially as described.

14. The combination in a hot-air engine, having a cylinder, crank and crank connection, of a working piston and a transfer-piston in said cylinder, a beam and a rod connecting the working piston with the crank, a chain connecting the transfer-piston with the crank, a yielding support carried by said crank to which the chain is connected, 3. spring carried by said support and surrounding the member to which the chain is connected, and means carried by the crank and adapted to contact with the spring, said action retarding the movement of the transfer- -piston.in the cylinder, substantially as described. 7

15. The combination in a hot-air engine, having a cylinder-crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, a connection between said crank and the transfer-piston, and means operated by said connection for relieving the pressure within said cylinder, substantially as de scribed.

16. The combination in a hot-air engine, having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder,a connection between said crank and the transfer-piston, a pipe leading from the interior of the cylinder to the atmosphere, a weighted armpivoted to the cylinder and serving to close said pipe, and means for tripping said arm whereby the pipe may be opened and the pressure within the cylinder relieved.

17. In a hot-air engine of the character described, a cylinder comprising an internal and an external casing, said internal casing having a straight upper edge, and an externallyflanged lower edge, and said external casing having upper and lower internal flanges, a packing interposed between the lower flanges of the casings, bolts passing through said flanges to secure thecasing together at the bottom, said upper flanges of the external casing having a groove forming an annular recess when both casings are fitted together, and securing means for holding said cylinder together at the top comprising fusible metal adapted to be run into said annular recess.

18. The combination in, a hot-air engine, having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, and means for regulating the pressure between said pistons so as to cause the transfer-piston to descend.

19. The combination in a hot-air engine, having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston in said cylinder, a flexible connection for raising said transfer-piston, and means for regulating the pressure between said piston and the working piston so as to cause the transfer-piston to descend.

20. The combination in a hot-air engine having a cylinder, crank and crank-shaft, of a working piston and a transfer-piston arrangedin said cylinder, means for raising and lowering said piston, a pressure-regulator for the cylinder, means for keeping said regula tor normally closed, and provision for operating said pressure-regulator by the connections for operating the transfer-piston. 21. The combination in a hot-air engine, having a cylinder, crank and crank-shaft,"of a working piston and a transfer-piston in said cylinder, means for raising and lowering said pistons within the cylinder, a relief-valve carried by said cylinder, andmeans connected therewith whereby it may be operated by the mechanism for raising the transfer-piston in the cylinder.

22. The combination in a hot-air engine, having a cylinder, crank and crank-shaft, of

V a working piston and a transfer-piston in said cylinder, means for raising and lowering said pistons within the cylinder, including a flexible connection for the transfer-piston, a relief-valve carried by the cylinder for regulating the pressure therein and a weighted arm carrying a seat for closing said valve, said weighted arm being engaged by the flexible connection of the transfer-piston when the pressure in the cylinder increases the normal speed of the pistons.

23. The combination in a hot-air engine of the character described, of the cylinder,-a working piston therein, a beam connected to and operated by, said piston,a pump, a'plunger therein, having a rod, a link connecting theplunger-rod with the beam whereby said rod may be raised and lowered, said link being in separable parts movable with relation to each other and so arranged as to be incapable of turning, and compressible means interposed between said parts to relieve the stroke of the piston.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

. MURRAY QIBOYER, J 0s. H. KLEIN. 

